The Bureau of Mines oil-shale program, initiated in April 1944, is concerned with the future utilization of oil shale in the United States as a source of liquid fuel. One phase of this program is the accumulation of information on the location, extent, and richness of oil-shale deposits that may'be suitable for processing to oil and related products. A previous publication presented, by means of logs, the oil yields of sections of the largest known oil-shale deposit in the country - the shales of the Green River formation occurring in adjoining portions of the states of Colorado, Utah, and Wyoming.